year, or be subjected to pasteurization under the supervision of the health authorities in case the herd is not tuberculin tested. 3. That no additions to any herd, whether the herd has been tested or not, shall be made in the future without subjecting the additional cattle to the tuberculin test. 4. That no license for the sale of milk shall in future be granted except to applicants having herds free of tuberculosis. 5. That the milk of cattle showing any of the udder affections above mentioned, or anthrax, rabies, gastro-enteritis, septic conditions, or clinical symptoms of tuberculosis, shall not be utilized as human food, even though the milk be pasteurized. Milk from cows fifteen days before and five days after parturition and that from animals receiving any of the deleterious medicaments or foodstuffs previously mentioned shall likewise be excluded. 6. That veterinary inspectors of the health department make frequent visits to dairies having untested herds, in order that they may discover all advanced cases of tuberculosis, or udder tuberculosis, as early as possible. 7. That the various States pass laws granting an appropriate indemnity to all owners of tuberculous cattle which come under their respective jurisdictions, the said animals to be slaughtered in abattoirs having Federal inspection. SOME IMPORTANT FACTORS IN THE PRODUCTION OF SANITARY MILK. By ED. H. WEBSTER, Chief of the Dairy Division. INTRODUCTORY. It is evident that in nature's scheme for the nourishment of the young milk was never intended to see the light of day, and if sucked from a normal, healthy gland it is the perfect food for the offspring. In this natural method of nourishment there is little possibility of contamination from outside sources. As soon as the artificial method of drawing milk is resorted to, however, there enters a whole set of conditions entirely new and different. The milk then comes in contact with the air, the vessel into which it is drawn, and with particles of dirt from many sources. Milk properly drawn, from healthy cows, in clean surroundings, handled in a sanitary manner, and delivered to the consumer in a comparatively short time, is free from disease-producing organisms and is ideal as a food. The problem of securing clean milk-i. e., milk as near as possible to the condition as it exists in the udder-is the problem of dairy sanitation. To put it in another way, it is the problem of reducing contamination from all outside sources to the least possible factor. Few cows, however, are properly milked; many herds are not free from disease; many farmers understand but little of sanitary methods, and but a small proportion of the milk coming into any city of considerable size can be delivered to the consumer soon after milking. HOW MILK IS CONTAMINATED. If the mere presence of solid particles of dirt so frequently found in the milk were the only damage wrought, the question would resolve itself into the simple operation of straining the milk or passing it through a clarifier. The presence of solid dirt is, however, an indication of much more serious conditions. Bacteriology teaches that every particle of dirt, whether it seems to the eye a source of contamination or not, carries with it great numbers of bacteria, and that milk at ordinary temperatures, 65° to 100° F., is an excellent medium for their growth, and most of the changes that take place in milk can be traced directly to such action. Neither straining nor clarifying will remove the bacteria from the milk; hence the necessity of keeping the dirt out, not straining it out. 55284 0811 161 From the act of milking to the final consumption of the milk the possibilities of contamination are many and varied in character. Everything that comes in direct contact with the milk may be a source of trouble, and many things may act indirectly and seriously affect the results desired. Contamination usually begins with the act of milking. If the udder and flanks of the cow are covered with the dirt of the yard or stable the process of milking will dislodge a greater or less portion of this filth, causing it to fall into the pail. The amount of filth that may be on a cow will depend very much on the conditions of the stable yard and the floor, gutter, and bedding in the stables. (See figs. 21, 23, 25, and 27.) As to the amount of filth that will get into the milk and its effect on the product, reports from the Illinois Experiment Station and the Storrs (Conn.) Experiment Station are here quoted: The average weight of dirt which falls from muddy udders during milking is 90 times as great as that which falls from the same udders after washing, and when udders are slightly soiled it is 32 times as great." Wiping the flank and udder of the cow with a damp cloth just before milking is a very efficient method for reducing the number of bacteria which falls into the milk pail. a Illinois Experiment Station, Bulletin 84. An average of 13 experiments at the Storrs station showed the following results: Bacteria in milk from unwiped udders per cubic centimeter___ 7,058 716 Decrease due to wiping---- 6, 342 The milker may not be cleanly in person or dress; he may have that most filthy of habits, milking with wet hands. The hands are usually wet by milking a few streams over them, and kept wet by repeating the operation from time to time. The filth on the udder will ooze out under and through the fingers and drip into the pail. This condition is frequently met in inspection work. FIG. 21.-Insanitary barnyard. Manure and filth evident everywhere. It is impossible to keep cows clean in such surroundings. Milkers too often wear clothing that has done duty for every other work about the farm. Such clothing may contain dirt from the hog pen, the chicken coop, the horse barn, or the swill barrel, and is entirely unfit to be worn during milking. A clean white milking suit has a twofold effect. It will not of itself contaminate the milk, and if the milker is required to keep such a suit clean he must of necessity keep everything with which he comes in contact clean. The difference in results between different milkers working under the same conditions is strikingly illustrated by Stocking. The average of 19 tests in which 2 milkers who had had no training in a Storrs Experiment Station, Bulletin 42. |